Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It discloses that no browser is launched, but omits whether a network request is made, what success or failure looks like, and whether any side effects occur.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is brief and free of filler; two sentences deliver the core purpose and one important caveat. However, brevity comes at the cost of missing necessary details.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the confusing, high-parameter input schema and no output schema, the description is substantially incomplete. It does not explain the return type, expected input, or behavior beyond the negative browser statement.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description adds no meaning to the input schema. The nine optional properties have unrelated, boilerplate descriptions (e.g., 'discarded after the shape check'), and the description does not indicate which parameter is the URL to check.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action ('check whether a URL can be opened') and a key behavioral caveat ('No browser is launched'), but it does not identify which of the nine input properties is the URL or clarify what 'can be opened' means. Sibling tools like browser-url-ok, fetch-status, and web-fetch create ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool over alternatives such as browser-url-ok, fetch-status, or web-fetch. The description only states a negative behavior and does not provide selection criteria.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.